The present invention relates generally to a wireline running and pulling tool for use especially by the oil, gas, water and geothermal industries.
It is of course necessary, for either operational reasons or safety reasons, to be able to release a wireline tool from a sub-surface tool attached thereto. However, the construction of the sub-surface tool may be such that the release is to be effected by an upwards hammer action or by a downwards hammer action. It is indeed first necessary for the wireline tool to have been attached to the sub-surface tool, but the location on the sub-surface tool of means for attachment to the wireline tool can vary. The axial distance along the sub-surface tool between its upper end and its said attachment means is usually referred to as its reach dimension.
Conventionally, separate and structurally distinct wireline tools have been provided for use with such different constructions and dimensions of sub-surface tools.
Commonly, the wireline tool has included a housing carrying latch means for releasable engagement with the sub-surface tool, and has further included a core capable of sliding longitudinally relatively to the housing to release the latch means from the sub-surface tool after a shear pin connecting the core to the housing has been broken by transmitting the hammer action through a tool string.
Attempts have naturally been made to reduce the range of wireline tools which may be required at different times, and the attention of the interested reader is directed to US Pat. No. 3,950,021 and EP No. 0,187,408 for further information.
It would nevertheless be of great advantage if just a single wireline tool could be provided, of a given diameter, which could be simply and easily adjusted without the need for additional parts to allow at least as good if not better universality than hitherto, by permitting either an upwards or downwards hammer action for release and/or by permitting attachment to sub-surface tools of different reach dimensions.